Study investigates the relationship between damage ratios of water pipes and seismic motion intensity after the earthquake of 2007 Niigata-ken Chuetsu-oki in Japan. The damage ratios of water distribution pipelines within a 2 km radius from the seismic observation stations are calculated in Kashiwazaki City, Niigata Prefecture.

To estimate damage ratios of water distribution pipelines, fragility curves were empirically obtained based on the damage datasets after  earthquake. Unfortunately, the number of seismometers was limited at that time, but earthquake, the number of seismometers has increased and various kinds of nationwide spatial data have become available. Under these circumstances, the methodology to estimate seismically-induced damages can be revised with analyzing the damage datasets from recent earthquakes. The geomorphological land classification map used in this study is 1:50000 scale, the digital map for Kashiwazaki – Higashi-Kubiki region developed by Takeuchi and Kawabata (2007).